See http://attempto.ifi.uzh.ch/acewiki/

1. AceWiki: Controlled English in a
Semantic Wiki
Tobias Kuhn
University of Zurich
Semantic Wiki mini series, Session 2
20 November 2008

2. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 2
AceWiki
 AceWiki is a new kind of semantic wiki
 Goals:
 Good usability (even for completely untrained
people)
 High expressivity (OWL and beyond)
 Approach:
 Articles are written in controlled English

3. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 3
Attempto Controlled English (ACE)
 Attempto Controlled English (ACE) is a controlled
natural language, concretely a subset of English
 Can be translated automatically and
unambiguously into various logical notations, e.g.
first-order logic, OWL, SWRL
 Supports a relatively large subset of natural
English:
 Proper names, nouns, verbs, adjectives, singular/plural,
relative phrases, anaphoric references, existential and
universal quantifiers, negation, conditional sentences,
question, and much more...

4. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 4
AceWiki: Screenshot

5. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 5
AceWiki: Words
 Proper names stand for individuals, e.g.
Switzerland, Bob Dylan
 Nouns stand for classes, e.g. country,
person
 Transitive verbs, of-constructs, and
transitive adjectives stand for binary
relations, e.g. owns, contains, part of,
friend of, located in, used for

6. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 6
AceWiki: Reasoning
 ACE is more expressive than OWL
 Since AceWiki currently uses an OWL reasoner, not
all ACE statement can be used for the reasoning:
 The reasoner is used for consistency checking,
individual classification, class hierarchy extraction,
and query answering

7. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 7
AceWiki: Consistency Check
 Each time a new sentence is added, AceWiki
checks whether it contradicts the current ontology
 If there is a contradiction then the sentence is
displayed in red font and not added to the ontology
(i.e. not used for reasoning)
 No reasoning without consistency!

8. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 8
Queries in AceWiki
 In AceWiki, articles can contain inline queries
expressed as ACE questions
 Some examples:
 Such questions are answered automatically by the
reasoner:

9. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 9
AceWiki: Predictive Editor
 ACE sentences are easy to understand, but writing
statements in ACE is more complicated because
the language restrictions have to be considered
 AceWiki provides a predictive editor that helps the
users to create syntactically correct sentences
 The predictive editor “looks ahead” and shows
word-by-word all possible continuations of a partial
ACE sentence

10. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 10
AceWiki: Editor

11. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 11
AceWiki: Technical Details
 AceWiki is currently in its alpha stage
 The reasoner Pellet is used (version 1.5.2)
 The ontology can be exported in OWL 2 format
 AceWiki is written in Java using the Echo Web
Framework making use of modern AJAX technologies
 Some important features are still missing: history/undo
facility, user management, ontology import, ...
 AceWiki and the ACE parser are available under the
LGPL license

12. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 12
AceWiki: Evaluation
 A usability experiment has been performed in order
to find out how easy or complicated it is to use
AceWiki
 The participants were asked to add general and
verifiable knowledge to the wiki
 No instructions how to deal with AceWiki
 80% of the created sentences were correct and
sensible
 61% of the correct sentences were complex (i.e.
contained a negation or an implication)

13. Tobias Kuhn, Semantic Wiki mini series, Session 2, 20 November 2008 13
That's all, folks!
 Thank you for your attention!
 More information can be found on the AceWiki
website:
 http://attempto.ifi.uzh.ch/acewiki/